Apple is facing mounting consumer pressure to address worker safety in its supplier factories, following growing speculation that the tech giant is "poisoning Chinese workers."

As a result, 80 environmental and human rights organisations and occupational health professionals from 27 countries have joined forces to demand Cupertino rectifies the working conditions of its staff.

In sending a letter to Apple Vice President of Environmental Affairs Lisa Jackson, the former head of the U.S. Environmental Protection Agency (EPA), the group is urging her to live up to her legacy by halting Apple’s poisoning of Chinese workers.

The cost of doing so, the groups estimate, is less than $1 per device.

Individuals wishing to take action on their smartphones to ensure the next iPhone is made without dangerous chemicals can visit www.greenamerica.org/bad-apple/app.cfm. To date, 20,000 consumers have signed a petition to Apple as part of the “Bad Apple” campaign.

The groups are specifically calling on Jackson to use her influence to eliminate and replace all hazardous chemicals used in Apple’s Chinese supplier factories with safe alternatives.

According to the groups, this is particularly critical for benzene and other highly hazardous chemicals which can cause cancer, reproductive and neurological harm.

At the EPA, Jackson monitored benzene levels in the water and air to ensure no one was exposed to dangerous levels of this known human carcinogen.

Jackson is in a unique position to make worker health and safety a priority in her second year at the company and according to the groups, Apple’s workers could be exposed to more than three times the amount of hazardous chemicals legally permissible in the U.S.

The letter from the groups, available here, notes that despite Apple’s Code of Conduct, 1.5 million workers are at risk for developing leukemia and other illnesses at work.

Thousands of chemicals are used in the process of making electronics devices, including many chemicals known to be carcinogens, reproductive toxins, neurotoxins and others that are largely untested.

“As a global technology leader, Apple can and should be the first consumer electronics company to implement reforms to protect workers from hazardous chemicals," claims Elizabeth O’Connell, campaigns director, Green America, the nation’s leading green economy organisation.

“Apple has the financial resources to make these changes and the global leadership to make it count.

"Apple is not alone in these offences, but its leadership is needed to make worker health and safety reforms a broader priority within the technology industry.”

Apple does not disclose a full list of the chemicals used in production, but two chemicals known to be used and of immediate concern include benzene and n-hexane, both of which have been linked to worker illness in Apple supplier factories.

The WHO’s International Agency for Research on Cancer (IARC) classifies benzene in Group 1 as it is known to be carcinogenic to humans and the US EPA classifies benzene in Group A, as a known human carcinogen for all routes of exposure. Prolonged exposure to benzene can cause leukemia. N-hexane is a neurotoxin that can cause nerve damage.

"For years Apple has carefully promoted an image that it is a company that "Thinks different"," adds Ted Smith, the executive director at the International Campaign for Responsible Technology (ICRT).

"Here is a golden opportunity for the company to really live up to this image by taking bold leadership to eliminate all hazardous chemicals that are harming the workers who make their products - most of whom are women of child-bearing age - and by replacing them with safe alternatives.”